tm510

You guys are lucky. I know fuel costs have skyrocketed in the US too, but here in Alberta, the increment for premium costs me about $7 a fill. Still, to me, not worth taking the chance, but it's more than that cheap beer offset.

Jerry

bt430

I've been running regular since day 1 four years ago no knocking, no issues.

stw

i've switched from regular to premium here and there, does that hurt at all?

carbuff

I am not a fuel expert, simply one who has owned many automobiles. It is my understanding that premium gasoline with an octane rating of no less than 90 prevents engine knocking in high powered engines.

I used regular 87 octane on every fill-up for my 2007 ES350 V6 powered car even though the operator's manual recommended preimum gasoline. The car never knocked nor became slugish or underpowered throughout my ownership.

However, it was my experience with a formerly owned 2006 M45 powered by a large V8 engine that using other than premium gasoline resulted in knocking and a diminished sense of overall power.

Where I live, the difference in cost between 91 octane premium gasoline and 87 octane regular gasoline is $.20 per gallon. My 2008 SC430 has a 19.8 gallon fuel capacity tank. If the tank was bone dry and I filled it with premium 91 octane gasoline, it would cost me $3.96 more than if I had used 87 octane regular gasoline.

Considering what the SC cost me, the difference in cost relating to premium vs. a lower octane gasoline is insignificant. I chose the SC for what it provides; that is luxury, beauty, a comfortable and quiet (not engine knocking sound) ride.

vwynn

iTrader: (4)

how come when someone compares gas.. its usually 87 or 91(93 in some states)


i never really see people talking out 89 octane fuel??

John007

well, guys let me first break it down to everyone DO NO USE REGULAR, OR PLUS GAS!!! You spent 60 + for a car and your going to mess it up!!! First off your car needs high octane to run... you can not go from high to low, but you can go low to high... thats how it works. Second off, your car is going to start to miss fire and shake... Plus you get better milage with premium anyways... Ok, think about this which do u rather have: drive a car with regular gas thinking that you will save a few pennies and get lower gas milage and a miss fire car thats going to cost you a few more hundred in teh long run, or spend the dam money and you save in the long run.I do hope this explains everything for you guys... tm510 HOLY **** BRO THATS A BLOW CROUCH 7 DOLLARS!!!

CAMAracer

iTrader: (1)

Actually from what I read I thought you can't go from low to high (most engines can't benefit from higher octane gas that it wasn't designed to use). But high to low is fine if you can live with the lower performance. Putting in 91 into my Celica isn't going to make a difference. Also, isn't higher octane rating more difficult to ignite, thus placing more strain on an engine that wasn't tuned to use it?

References:

1) http://www.wisegeek.com/what-is-high-octane-fuel.htm

2) http://www.wanderings.net/notebook/M...orth-the-money

3) http://auto.howstuffworks.com/question90.htm

4) http://www.answerbag.com/q_view/55193

KSUFlasher

Seems like a lot of people put in 'lower' grade gas. I never have, just not worth the risk to me. Maybe if I leased or only plan to keep my care a year or two. However, I figure that the better care I take of my car, the better and longer it will take care of me.

roadrage

I had an SC400 and always put 87 Octane never had a problem. Never had a pinging or performance problem. Since I've had my SC430 I've put 87 Octane and haven't had a problem either. Performance is still there.

What promted me to do this when i had my SC400 was when I was filling up my tank at Costco. This man with an LS430, whos filling up next to me tells me, I've been filling up my tank with regular this whole time and I have never had a problem with it. So ever since that day i did and he was right! No problem!!!

Its all about preference. My friend will only buy premium gas at Cheveron for her Lexus, even if its 25 cents more than Costco's premium gas. Nothing less. That Techron cartoon commercial sure won her over!!!

ratha67

[QUOTE=roadrage;3621313]I had an SC400 and always put 87 Octane never had a problem. Never had a pinging or performance problem. Since I've had my SC430 I've put 87 Octane and haven't had a problem either. Performance is still there. QUOTE]



I never fill up with anything but 87 octane. I've had two SC400's. One went 460,000 miles, and never gave me any problems (except power steering pump, A/C compressor, and alternator). The other went 320,000 miles without any problems (except power steering pump). Both of those cars were running smooth (no pings, knocks, or shakes on the day I sold them)

When I got a Mercedes, the dealer convinced me to use premium only, telling me low octane would kill the engine. I pumped 91 octane for about a year and decided to go back to my old ways. I'm at 150,000 miles on the Mercedes, and haven't had a problem (except Mass Air Flow sensor and wheel bearings).

I think it all comes down to keeping up with the maintenance and not abusing your cars. I spend extra money on synthetic oil and good filters, and make sure to change all of the fluids myself at regular intervals.

I'm not knockin' on anyone who pumps premium...that's what you're supposed to do, that's what the manual says, and its probably better for your car. I just haven't experienced negative results from pumping regular and I'm cheap. If you do the math with how many miles I've driven, 20 cents less a gallon adds up.

thang tran

In my hometown Vietnam 1980s , gas was very expensive , we used to mix gas and a portion of diesel (cheap) for car or boat engine , it saved a lot gasmileage , but I remembered one thing , engine ran hotter and of course , enguine rebuilt happened sooner , but in the poor country , mechanic labor not a big deal , have you ever looked at the temperature gauge in the summer when you run with low octan gas , if engine temperature changed , it would be a problem , another question , how many Lexus lessee put premium gas in the cars that they do not own them and leasing cars returned to market under certified ???

TLW

Just tried a tank of 87 the other day and no problems. It was just a test.

G02

I was on the fence about putting regular in my baby.I did it yesterday and to my surprise the car ran great and my info center showed a 1.5 mpg increase,go figure

carbuff

When I had my ES350, I ran it from day one on 87 octane gasoline. Never had a knock, ping or decrease in engine performance. I can not say this for V8 cars I have owned.


It was my practice to do a modest test of low octane gasolines on my V8 cars to determine if they could run on the lower priced gasolines. None could. All began to ping.


For some reason, I am unnwilling to try a low octane gasoline on my SC430. I have read many posts regarding this subject. However, I came across some data that convences me that I should not tempt fate. You might find the information of value and helpful in making your decision about the gasoline to use in your V8.

http://www.mikuni.com/tg_detonation.html

Although motorcycles are referenced, I believe that all internal combustion engines are governed by the same octane factors. That is, if the mfg sets the engine to burn a particular fuel, one should heed the instruction and burn that fuel.

You be the judge.

Jackalope

Yeah, I know it says "Premium unleaded fuel only"....but I've been putting the midgrade stuff in. My boss says he puts regular in his. Neither of us have noticed any sort of problem. Anyone have any ideas on why you're supposed to put the expensive stuff in there?

BTW - Yes, my gas mileage is the same and I haven't noticed any difference in power or drivability.